# Consumer Surplus Calculator

URL: https://speedycalculator.com/calculators/finance/consumer-surplus/
Last updated: 2026-10-25

> The consumer surplus calculator works out consumer surplus – the difference between what buyers are willing to pay and what they actually pay – for a linear demand curve, plus producer surplus with a linear supply curve.

## Inputs

- Maximum price (demand curve intercept)
- Market (equilibrium) price
- Quantity sold
- Minimum supply price (supply curve intercept)

## Results

- Consumer surplus
- Producer surplus
- Total surplus

## Formula

```
Consumer surplus = ½ × (maximum price − market price) × quantity
Producer surplus = ½ × (market price − minimum supply price) × quantity
Total surplus = consumer + producer surplus
```

## Explanation

Consumer surplus is the triangle under the demand curve and above the price. Price ceilings, taxes and monopolies change the surpluses and can create deadweight loss.

### How to use the Consumer Surplus Calculator

- **Maximum price (demand curve intercept)**
- **Market (equilibrium) price**
- **Quantity sold**
- **Minimum supply price (supply curve intercept)**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the maximum price buyers would pay (demand intercept), the market price, the quantity sold and the minimum price sellers accept (supply intercept).

### Tips

- Use consistent periods (a year or a quarter) for flow figures and period-end values for balances.
- Average opening and closing balances when a ratio mixes a flow with a stock.
- Benchmark against competitors in the same industry.
- Read the ratio together with others – profitability, liquidity and efficiency tell different stories.

### Common mistakes to avoid

- Using sales instead of cost of goods sold for inventory ratios.
- Mixing gross, operating and net profit.
- Ignoring one-off items that distort a single year.

### Inputs explained

FieldWhat to enterMaximum price (demand curve intercept)Amount in your currencyMarket (equilibrium) priceAmount in your currencyQuantity soldA numberMinimum supply price (supply curve intercept)Amount in your currency

### What each result means

- **Consumer surplus** = 0.5×([Maximum price (demand curve intercept)] - [Market (equilibrium) price])×[Quantity sold]
- **Producer surplus** = 0.5×([Market (equilibrium) price] - [Minimum supply price (supply curve intercept)])×[Quantity sold]
- **Total surplus** = [Consumer surplus] + [Producer surplus]

### Example values

How the main result changes when **Maximum price** changes and everything else stays at the example values above:

Maximum price (demand curve intercept)Consumer surplus25-2,50037.53,7505010,00062.516,2507522,50010035,000

## Worked example

Inputs — Maximum price (demand curve intercept): $50; Market (equilibrium) price: $30; Quantity sold: 1,000; Minimum supply price (supply curve intercept): $10.

Results — **Consumer surplus = $10,000.00**; Producer surplus = $10,000.00; Total surplus = $20,000.00.

## FAQ

**What is consumer surplus?**
The benefit buyers get from paying less than they'd be willing to.

**How do taxes affect consumer surplus?**
They raise prices and reduce quantity, shrinking surplus.

**What is producer surplus?**
What sellers receive above their minimum acceptable price.

**What formula does the Consumer Surplus Calculator use?**
Consumer surplus = ½ × (maximum price − market price) × quantity.


## Sources

- [Corporate Finance Institute – financial ratios](https://corporatefinanceinstitute.com/)